Conventionally, bodily fluid-absorbent wearing articles such as disposable diapers or menstruation napkins are known including a liquid-pervious topsheet, a liquid-impervious backsheet and a bodily fluid-absorbent core interposed between the top- and backsheets. It is known to form the topsheet on one of its surfaces with a first group of crests and troughs alternately arranged to extend in parallel in one direction, and with another group of crests and troughs alternately arranged to extend in parallel in a direction orthogonal to the former group of crests and troughs. It is also known to utilize such a topsheet in a manner such that the crests and the troughs face the wearer's skin.
For example, JP 1983-132155 A (PTL 1) discloses a liquid-pervious nonwoven fabric suitable for use as a topsheet in a disposable diaper or the like. This nonwoven fabric has crests and troughs extending in parallel in a machine direction in the manufacturing process of the nonwoven fabric. The density of the nonwoven fabric is higher in the troughs than in the crests.
JP 2008-25079A (PTL 2) also discloses a liquid-pervious nonwoven fabric suitable for use as a topsheet in a disposable diaper or the like. This nonwoven fabric is generally flat on one surface thereof and formed on the other surface with crests and troughs extending in parallel in a machine direction and similar crests and troughs extending in parallel in a cross direction orthogonal to the machine direction. The nonwoven fabric has a higher density in the crests than that in the troughs.
WO 2008-146541 A1 (PTL 3) discloses a laminate of sheet elements. According to one embodiment, the laminate consists of a first sheet element and a second sheet element laminated together, and both the first and second sheet elements contain thermoplastic fibers. The first sheet element is formed with a plurality of through-holes having the same longitudinal direction. In addition to the through-holes, the first sheet element is formed with a plurality of grooves along the longitudinal direction of the through-holes. The first sheet element and the second sheet element are fusion bonded to each other in a plurality of joint debosses.